The present invention is directed to an apparatus for processing of semiconductor wafers, and in particular, a lift and rotate assembly for use in a workpiece processing station.
During the manufacture of semiconductor integrated circuits and other semiconductor articles from semiconductor wafers, it is often necessary to perform several processing steps in one or more processing stations. In order to more fully automate the process and minimize operator handling, tool architectures have been developed incorporating multiple processing stations and automated means for moving semiconductor wafers from one processing station to the next.
When developing a tool architecture one consideration is the overall size of a tool. One reason for this is because the manufacture of semiconductor integrated circuits typically take place in a clean room environment, where the creation and maintenance of clean room space has a relatively higher cost, which is related to the size of the space. As a result, efforts and developments which reduce the overall tool size can have a significant cost benefit.
Tool size can often be an important consideration when adding to and/or updating a particular tool in a line. If the size and shape of the new tool is equal to or smaller than the available space or the space created by the removal of the old tool being replaced, the impact on nearby tools is minimized. In contrast, when a new or replacement tool is larger than the available space or the space required by the previous tool, it can potentially require the adjustment and/or relocation of the placement of nearby tools.
One reason to update one or more tools in a semiconductor manufacturing line is to make a transition from a smaller to a larger wafer size. The use of larger wafer sizes is desirable because it enables a greater number of devices to be manufactured on each wafer. By producing more devices on each wafer the cost of manufacturing each device can often be reduced.
Whereas the present standard wafer size for a majority of semiconductor manufacturing lines is 200 millimeters, there is an increasing trend toward the use of 300 millimeter wafers. Therefore, efforts at minimizing or maintaining tool size, while enabling the tool to handle larger wafer sizes would similarly be beneficial.
Another consideration when developing a tool architecture is ease of maintenance. Occasionally individual processing stations or portions thereof, need to be removed for regular cleaning and/or maintenance, or replacement. The easier it is to service the assembly or subassembly requiring maintenance, the less time a tool will be down or out of service.
Ease of maintenance becomes especially important when one considers that, as previously noted, semiconductor manufacturing tools are often located in a clean room environment. In clean room environments, personnel are typically required to wear protective clothing including gloves, coats, masks, etc., which can make even routine tasks more cumbersome. Therefore, improvements in accessibility of installed assemblies and/or subassemblies and the ease of installation and/or removal of the same would similarly be beneficial.